I am going to use shellac for my first time. I’m either going to brush or pad it on. I’ve read a couple of things on the web written by Jeff Jewitt about scuff sanding between coats.
My question is how long do I wait between coats. Often he has written, let it dry overnight. I guess I wondering if this is a 24 hour period or less (12 hour?). The reason I’m asking is because this project is meant to be a Christmas present.
-Todd
Replies
Shellac can be recoated very quickly. In a reasonably warm and dry (70°, 50% rel. humidity) environment, you can apply a second wiped on coat in 15 minutes, and a third coat 30 minutes after that. Subsequent coats require more drying time. Two hours would almost always be enough for wiped on shellac, though after every three or four coats you should let it more fully dry overnight--12 hours. Padding on works best with a fairly light cut--1 lb. or 1 1/2 lb.
Brushing shellac applies thicker coats and therefore require more time between coats. Yuo can use 2 lb. cut with brushing. Use only artist's watercolor wash brushes such as those with Taklon gold bristles. A 1 1/2 " brush may be $15.
There is an easy way to judge if you are waiting enough between coats. If the wiping rag or brush begins to drag at all STOP immediately. That means the coat being applied is pulling up the previous coats.
Work quickly, in one direction and do not go back to get a missed spot--you'll get it the next coat.
I tend to put down several layers in a few hours when padding shellac. Light, very thin coats will dry in a few minutes; as long as the pad isn't sticking, you can make another pass. The end result is a mirror shiny finish.
I don't scuff sand shellac between coats, unless there is some crud that needs to be sanded out. A new layer of shellac will melt into the previous layer, therefore no sanding is needed to help adhesion between layers.
If a satin finish is desired, rub out the shellac after 24 hours using a grey 3M pad.
As I understand shellac, it dries quickly and basically the next "coat" you put on becomes one with the previous coat becauses it amalgamates into the previous finish. I guess the question might be, how many "coats" makes the finish you need/want.
That is paartially true. It is still possible to sand through one coat and have a subtle ring effect, where you penetrated into the next coat, which is discrete from the top coat. The coatsadhre to each other and probably partially blend together. If a lower coat is more cured it may not be melted before the topcoat is dry. I'm not sure what happens chemically.
Jay
This forum post is now archived. Commenting has been disabled